TDDKit

You are now leveled up in your test driven development experience in Swift. 🚀

Overview

TDD is a great way to write code. It improves code quality and brings great joy. 😊

But it also brings a lot of boilerplate. 🤬

TDDKit is designed with TDD in mind. These opinionated helpers keep you writing great tests that are clear, concise and to-the-point.

🫵😎🎉

For a full list of features and usage please see the documentation

Sample Use

final class SampleUseTests: XCTestCase {
    func test_failingGetUsername_createPoem_fails() async throws {
        let error = XCTAnyError()
        let (sut, _) = makeSUT(getUsernameResult: .failure(error))

        let capturedError = await XCTCaptureError(from: try await sut.createPoem())

        XCTAssertCastEqual(capturedError, error)
    }

    func test_createPoem_callsService() async throws {
        let (sut, spy) = makeSUT()

        _ = try await sut.createPoem()

        XCTAssertContainsEqual(spy.messages, [.getUsername])
    }

    func test_createPoem_succeeds() async throws {
        let name = UUID().uuidString
        let (sut, _) = makeSUT(getUsernameResult: .success(name))

        let capturedPoem = try await sut.createPoem()

        XCTAssertContainsEqual(capturedPoem, "Once upon a time... there was a \(name)")
    }

    // MARK: - helpers
    private func makeSUT(
        getUsernameResult: Result<String, Error> = .success(.init()),
        file: StaticString = #file,
        line: UInt = #line
    ) -> (sut: PoemCreator, spy: Spy) {
        let spy = Spy(getUsernameResult: getUsernameResult)
        let sut = OUATPoemCreator(service: spy)

        XCTAssertWillDeallocate(instance: sut, file: file, line: line)
        XCTAssertWillDeallocate(instance: spy, file: file, line: line)

        return (sut, spy)
    }

    private final class Spy: XCTCustomDebugStringConvertible, UserService, UserServiceDefaults {
        enum Message: XCTCustomDebugStringConvertible { case getUsername }

        private let getUsernameResult: Result<String, Error>

        init(getUsernameResult: Result<String, Error>) {
            self.getUsernameResult = getUsernameResult
        }

        private(set) var messages: [Message] = []

        // MARK: - UserService
        func getUsername() async throws -> String {
            messages.append(.getUsername)
            await Task.yield()
            return try getUsernameResult.get()
        }
    }
}

Check out the full test: SampleUseTests.swift

Installation

Xcode Project

Add this package as a dependency to the test target of your Xcode project.

1. Xcode Menu > File > Add Packages...
2. Paste this project's URL to the "Search or Enter Package URL" field. (https://github.com/andybezaire/TDDKit)
3. Select TDDKit product and add it to your project's test target Note: NOT your main target.
4. Press "Add Package" button.

Swift Package Manager (SPM)

Add this package as a dependency to the test target of your Swift package.

// swift-tools-version: 5.8
import PackageDescription

let package = Package(
    name: "SampleProduct",
    products: [
        .library(name: "SampleProduct", targets: ["SampleProduct"])
    ],
    dependencies: [
        .package(name: "TDDKit", url: "https://github.com/andybezaire/TDDKit.git", from: "1.0.0")
    ],
    targets: [
        .target(name: "SampleProduct", dependencies: []),
        .testTarget(name: "SampleProductTests", dependencies: ["SampleProduct", "TDDKit"])
    ]
)

Documentation

It is recommended to add the documentation to your documentation browser for the most immersive experience. 😎

The documentation can be generated from this package using:

swift package generate-documentation --include-extended-types

Note: This package includes mainly extensions, so the --include-extended-types flag is neccesary.

The documentation for the latest version is also available on GitHub

More Info and Feature Requests

Please do not hesitate to open a GitHub issue for any questions or feature requests.

License

"TDDKit" is available under the MIT license. See the LICENSE file for more info.

Credit

Copyright (c) 2023 Andy Bezaire

Created by: andybezaire